Re: [PATCH 1/3] tag: use skip_prefix instead of magic numbers

> Jacob Keller <jacob.e.keller@intel.com> writes:
> 
> > From: Jeff King <peff@peff.net>
> >
> > Make the parsing of the --sort parameter more readable by having
> > skip_prefix keep our pointer up to date.
> >
> > Signed-off-by: Jeff King <peff@peff.net>
> > Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
> > ---
> >  builtin/tag.c | 14 ++++----------
> >  1 file changed, 4 insertions(+), 10 deletions(-)
> >
> > diff --git a/builtin/tag.c b/builtin/tag.c
> > index ef765563388c..7ccb6f3c581b 100644
> > --- a/builtin/tag.c
> > +++ b/builtin/tag.c
> > @@ -524,18 +524,12 @@ static int parse_opt_sort(const struct option *opt, const char *arg, int unset)
> >  	int *sort = opt->value;
> >  	int flags = 0;
> >  
> > -	if (*arg == '-') {
> > +	if (skip_prefix(arg, "-", &arg))
> >  		flags |= REVERSE_SORT;
> > -		arg++;
> > -	}
> > -	if (starts_with(arg, "version:")) {
> > +
> > +	if (skip_prefix(arg, "version:", &arg) || skip_prefix(arg, "v:", &arg))
> >  		*sort = VERCMP_SORT;
> > -		arg += 8;
> > -	} else if (starts_with(arg, "v:")) {
> > -		*sort = VERCMP_SORT;
> > -		arg += 2;
> > -	} else
> > -		*sort = STRCMP_SORT;
> > +
> 
> By losing "*sort = STRCMP_SORT", the version after this patch would
> stop clearing what is pointed by opt->value, so
> 
> 	git tag --sort=v:refname --sort=refname
> 
> would no longer implement the "last one wins" semantics, no?
> 
> Am I misreading the patch?  I somehow thought Peff's original was
> clearing the variable...
> 
> >  	if (strcmp(arg, "refname"))
> >  		die(_("unsupported sort specification %s"), arg);
> >  	*sort |= flags;